Related Experiment Video
Updated: Jan 30, 2026
06:16
Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing
Published on: April 25, 2019
8.0K
Controlling femtosecond filament propagation using externally driven gas motion
Optics Letters
|January 16, 2019
Summary
Controlled air motion steers femtosecond laser filaments by manipulating the thermal density depression. This research demonstrates precise control over filament propagation, opening new avenues in nonlinear optics.
Area of Science:
- Physics
- Optics
- Nonlinear Optics
Background:
- High-repetition-rate femtosecond filaments in air create a thermal density depression, acting as a negative lens.
- This density hole influences the filament's own propagation dynamics.
Purpose of the Study:
- To investigate the impact of externally driven gas motion on femtosecond filament propagation.
- To control and steer femtosecond filaments by manipulating the associated density hole.
- To derive conditions for maximizing the steering effect and explore applications.
Main Methods:
- Generating femtosecond filaments in air at high repetition rates.
- Applying externally driven gas motion using an audio speaker-driven sound wave.
- Analyzing the interaction between the density hole and filament propagation.
Main Results:
- Externally driven gas motion can effectively steer femtosecond filaments.
- An expression for optimal gas velocity to maximize steering was derived.
- At higher velocities, the density hole is displaced, decoupling it from the filament.
- Controllable and repeatable filament deflection was demonstrated.
Conclusions:
- This study presents the first demonstration of controlling femtosecond filament propagation via controlled motion of the nonlinear medium.
- The findings enable precise steering of laser filaments, with potential applications in quasi-phase matching for gas-based nonlinear optics.
Related Concept Videos
01:20Gas Exchange and Transport
76.9K
Gas exchange, the intake of molecular oxygen (O2) from the environment and the outflow of carbon dioxide (CO2) into the environment, is necessary for cellular function. Gas exchange during respiration occurs largely via the movement of gas molecules along pressure gradients. Gas travels from areas of higher partial pressure to areas of lower partial pressure. In mammals, gas exchange occurs in the alveoli of the lungs, which are adjacent to capillaries and share a membrane with them.
76.9K
03:19Gas Laws: Boyle's, Gay-Lussac, Charles', Avogadro's, and Ideal Gas Law
77.3K
Through experiments, scientists established the mathematical relationships between pairs of variables, such as pressure and temperature, pressure and volume, volume and temperature, and volume and moles, that hold for an ideal gas.
77.3K
01:11Work Done on a System by External Force
3.0K
The work done by an external force on a particle changes its kinetic energy. However, internal forces must also be considered for a system of interacting particles. The potential energy formulation helps formulate the effect of internal forces. The net work done by an external force can be written in terms of the total change of mechanical energy, which includes both kinetic and potential energies.
In the presence of a non-conservative opposing force, like friction, some part of the work done...
In the presence of a non-conservative opposing force, like friction, some part of the work done...
3.0K
01:07Propagation of Waves
3.0K
When a wave propagates from one medium to another, part of it may get reflected in the first medium, and part of it may get transmitted to the second medium. In such a case, the interface of the two mediums can be considered as a boundary that is neither fixed nor free.
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
Consider a scenario where a wave propagates from a string of low linear mass density to a string of high linear mass density. In such a case, the reflected wave is out of phase with respect to the incident wave, however the...
3.0K
02:34Kinetic Molecular Theory and Gas Laws Explain Properties of Gas Molecules
37.4K
The test of the kinetic molecular theory (KMT) and its postulates is its ability to explain and describe the behavior of a gas. The various gas laws (Boyle’s, Charles’s, Gay-Lussac’s, Avogadro’s, and Dalton’s laws) can be derived from the assumptions of the KMT, which have led chemists to believe that the assumptions of the theory accurately represent the properties of gas molecules.
37.4K
01:23Propagation of Action Potentials
9.4K
The propagation of an action potential refers to the process by which a nerve impulse, or "action potential," travels along a neuron.
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
Neurons (nerve cells) have a resting membrane potential, with a slightly negative charge inside compared to outside. This is maintained by ion channels, such as sodium (Na+) and potassium (K+) channels, which control the flow of ions. When a stimulus, like a touch or a signal from another neuron, triggers the neuron, sodium channels open, allowing sodium ions to...
9.4K